Arginine
Also known as L-arginine
Arginine is a conditionally essential amino acid, meaning the body usually makes enough but may need extra from food during illness, injury, or rapid growth. It is the direct precursor to nitric oxide, which relaxes blood vessels.
Why it matters
What it does in your body
- Precursor to nitric oxide for blood flow
- Part of the urea cycle that clears ammonia
- Supports immune function and wound healing
- Precursor to creatine
Intake guidance
How much you need
There is no established daily requirement, because a healthy body makes its own arginine and dietary protein supplies more. It can become conditionally essential during serious illness, trauma, or in premature infants, when needs outpace what the body can make.
What affects it
What affects your intake
Body's own production
Healthy adults synthesize arginine through the urea cycle, so diet is rarely the limiting factor.
Illness and healing
Severe burns, trauma, and sepsis raise demand enough that arginine is considered conditionally essential in those settings.
Protein intake
Any protein-rich diet, especially nuts, seeds, meat, and legumes, supplies plenty.
In practice
Good to know
Good to know: arginine is popular as a supplement for blood flow, exercise pumps, and erectile function because it feeds nitric oxide. Results are mixed, and the related amino acid citrulline is often absorbed better and used instead. For most people, food supplies all the arginine the body cannot make itself.
Where to get it
Best food sources
The bottom line
Your body makes arginine and food supplies the rest, so deficiency is not a concern for healthy people. Supplements target blood flow, with mixed evidence.
Track arginine automatically
Arginine is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.
Sources and method
The classification, roles, and guidance on this page come from the references below, drawing on the Institute of Medicine (now the National Academies) Dietary Reference Intakes and reputable nutrition science.
- Institute of Medicine (2005), Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
- National Library of Medicine, MedlinePlus
This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.